I think you want sprintf "%1.2E" which will force scientific notation.

From perldoc -f sprintf:

       %e   a floating-point number, in scientific notation
       %f   a floating-point number, in fixed decimal notation
       %g   a floating-point number, in %e or %f notation
  ...
       %E   like %e, but using an upper-case "E"
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Hope this helps